mysql - 统计记录中有超过 1 个 child 的家庭

Question

这是我的查询，但需要很长时间才能完成。

SELECT count(*) AS count_all 
FROM families 
WHERE family_status_cat_id = 1374 
      AND (SELECT COUNT(*) FROM childrens WHERE family_id = families.id) > 1 
      AND unit_id IN (49,33,74,327,329,453,454,469,472,546,547) 

有没有办法让它变得更好？

Answer 1

您的查询可能会在正确的索引下正常工作。我建议以下两个:

create index families_fsc_unitid on families(family_status_cat_id, unit_id);
create index children_familyid on children(family_id);